Doors for motor vehicles include side impact counter measures such as foam pads or brackets that are placed between a trim panel and a door frame or a bolster that is attached to the door frame. The padding or brackets are capable of absorbing significant amounts energy at a force-deflection rate safe for occupants. In a side-impact collision, the occupant strikes the door and experiences a reaction force. The foam pads or brackets exert a reaction force through a range of displacement during a collision.
To reduce the risk of serious injury, the reaction force exerted upon the occupant should be kept below 6 kN through at least 55 mm. The force exerted upon the vehicle occupant will depend upon a number of factors, including the severity of the impact, the structural characteristics of the side impact counter measures, and the mass of the occupant.